Severe (or more) turbulence... how common?

But for sure
I lost 2000' (I couldn't believe it when I looked at the altimeter after
recovering the plane...

[...]

I don't know whether this was "severe turbulence" according to
the definition. [...] I did keep the plane under
control - my main concern being to avoid hitting Vne.


Unless you intended to lose 2000 feet, I'd say the plane was not under control.
The wings may have been level, but two thousand uncommanded feet of altitude
loss qualifies to me as severe turbulence. And whether it was smooth or not is
irrelevant - bumpy air is "chop", altitude deviations are "turbulence". Sort
of.

Jose

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